A038769 Number of digits of n which are divisors of n.

1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 2, 2, 1, 1, 2, 1, 1, 1, 1, 1, 1, 2, 0, 2, 1, 1, 0, 1, 0, 1, 1, 1, 2, 0, 1, 2, 0, 0, 1, 1, 1, 1, 0, 2, 1, 0, 0, 2, 0, 1, 1, 1, 0, 0, 2, 0, 0, 0, 0, 1, 1, 1, 1, 1, 1, 2, 0, 0, 0, 1, 1, 1, 0, 0, 1, 0, 2, 0, 0, 1, 1, 1, 0, 1, 1, 0, 0, 2, 0, 1, 1, 1, 1, 0, 1, 1, 0, 0, 2, 1, 2, 2, 1, 2, 2

Offset: 1

Author

Henry Bottomley, May 04 2000

Keywords

• nonn
• base
• easy

Comments

a(A038772(n)) = 0; a(A038770(n)) > 0.

Examples

			a(35)=1 because 5 is a divisor of 35 but 3 is not.
		

Links

• Reinhard Zumkeller, Table of n, a(n) for n = 1..10000

Crossrefs

Cf. A034709, A034837, A038770, A038772.

Programs

Haskell

import Data.Char (digitToInt)
a038769 n = length $ filter (== 0)
            $ map ((mod n) . digitToInt) $ filter (> '0') $ show n
-- Reinhard Zumkeller, Jun 19 2011

Magma

[#[c:c in Intseq(k) |not IsZero(c) and k mod c eq 0]:k in [1..105]]; // Marius A. Burtea, Dec 23 2019

Maple

f:= proc(n) local L; L:= convert(n,base,10);
  nops(select(t -> t > 0 and n mod t = 0, L))
end proc:
map(f, [$1..1000]); # Robert Israel, Jul 04 2016

Mathematica

Array[Count[Position[Most@ DigitCount@ #, ?(# > 0 &)][[All, 1]], k /; Mod[#, k] == 0] &, 105] (* Michael De Vlieger, Dec 23 2019 *)
Table[Count[n/Select[IntegerDigits[n],#>0&],?IntegerQ],{n,110}] (* _Harvey P. Dale, Mar 04 2023 *)